The present invention relates generally to the field of foot weight alarm devices and, more specifically, to weight alarming devices capable of alarming an individual's weight without restricting the individual's movement.
More than 500,000 hip and knee replacements are performed each year in the United States. There are over 250,000 hip fractures each year, with most requiring open reduction and internal fixation. In addition, the number of multiple trauma victims with lower extremity fractures each year is substantial. Individuals who have suffered a stroke may be required during rehabilitation to relearn the ability to control their body over a relatively small base in two-legged stance. In order for an individual to effectively convalesce and rehabilitate in the above-mentioned cases, or from any other injuries or surgery to the lower extremities, it is essential that the individual effectively control the amount of weight applied to the lower extremities. Accordingly, accurate and immediate detection and communication of the weight being applied is imperative.
Detection of the weight applied to the lower extremities is achieved through the use of an external sensing device employing some type of means to convert the weight applied into a signal. Such external sensing device can be a foot force sensor attached directly to the injured person's foot or inserted in, or in some manner attached to, his or her shoe. The signal is then conveyed to a device which communicates to the injured person whether a predetermined weight limit is reached. Such communication can be in the form of a sensory alarm; either visual, audible or tactile. In this way the injured person is advised that the weight being applied to the lower extremity is below, within or above a predetermined limit or desired weight range. This informs the injured person that he or she is not providing sufficient weight to encourage healing, is providing the proper amount of weight, or is providing excessive weight and, therefore, in danger of deleteriously affecting the lower extremity and impeding convalescence or rehabilitation. The injured person can then increase or reduce the amount of weight being applied to the lower extremity.
There are a number of weight alarming devices currently known and in use. These devices communicate either an alarm "on" or "off" state based upon a single predetermined weight limit without the ability to communicate multiple weights or weight ranges, or to communicate certain percentages of a predetermined weight or weight ranges. Therefore, by the time the alarm actuates, the injured person is already at, and possibly has exceeded, the predetermined weight or weight ranges and may be sustaining damage to the lower extremity without any forewarning. Also, these devices do not communicate to the injured person that more weight should be placed on the lower extremity to encourage bone growth and healing.
Accordingly, a need exists for a device for alarming foot weight for use with a foot force sensor which overcomes the above drawbacks.